1. Field of the Invention
The invention relates to an electric vehicle having a traction electric motor, such as a pure electric vehicle, a hybrid vehicle, or a fuel cell vehicle.
2. Description of Related Art
An electric vehicle includes a traction electric motor, and an inverter that converts direct-current power of a battery into alternating-current power that is suitable to drive the electric motor. Since the inverter handles large current in order to drive the electric motor, the inverter produces a large amount of heat. That is, the electric vehicle has at least two heat-producing sources that include an electric motor and an inverter. Each heat-producing source is provided with a cooling apparatus in order to restrain temperature rise of the heat-producing source.
Typically, liquid (water, long life coolant (LLC) or oil, for example) is used as a coolant. If the coolant leaks, the cooling capability significantly declines. A technology that detects leakage of a coolant is proposed in Japanese Patent Application Publication No. 2008-309134 (JP 2008-309134 A). Furthermore, a technology that lessens the amount of leakage of a coolant caused when the coolant passage is damaged is proposed in Japanese Patent Application Publication No. 2010-276035 (JP 2010-276035 A).